Closure for paper containers



April 3, 1951 D. KIRK 2,547,871

CLOSURE FOR PAPER CONTAINERS Filed July 8, 1947 INVENTOR DOUGLAS KIRK.

ATTORNEYS Patented Apr. 3, 1951 CLOSURE FOR PAPER CONTAINERS Douglas Kirk, Hudson, Ohio, assignor to The Quaker Oats Company, Chicago, 111., a corporation of New Jersey Application July 8, 1947, Serial No. 759,601

1 Claim.

The present invention relates to the manufacture of containers, cartons or the like, primarily intended for packaging of cereals, flours or other commodities, for which it is desired to provide a discharge or pouring opening with a closure which may be easily removed and replaced. In the designing of such a removable closure it is desirable to provide a closure which can be readily removed and when replaced will be retained in the opening, be incapable of accidental displacement and maintain a reasonably tight seal so that the contents of the package will not deteriorate. For this purpose the closure should preferably snap into place without danger of injuring the material of the container around the pouring opening.

It is also desirable to provide a closure of the type specificed which will not increase the cost of the container materially. A number of devices for the general purpose have been designed which, however, increase the cost of the package unduly. Other closures have been designed which cannot be easily and securely replaced. It is the purpose of the invention to design a closure which is free of these defects.

The containers which are contemplated here are to be made of cardboard, strawboard, fiberboard or similar paper stocks, and the closure is made of a like material without loss of stock so that there is a negligible increase in the actual the closures such as shown and described herein.

While the invention is disclosed in several forms and embodiments, it is not limited to the exact embodiments, but may be varied and modified cost of providing containers of this type with' within the scope of the invention as set forth in the claim.

In the drawings in which the best known and preferred forms of the invention are shown:

Fig. 1 is a view looking at the top of a cylindrical container provided with the improved 010- Fig. 5 is a section on the line 5-5 of Fig. 4;

In this view the outer Wrapper which is usually applied about the carton is shownin dotted lines.

Fig. 6 is a perspective view of a six-sided carton to which the outer wrapper has been applied,

this view showing the start of the closure removing operation.

Fig. 7 is a view similar to Fig. 5, but showing the closure lifted above the pouring opening.

Fig. 8 is a view showing a modification of the cylindrical carton.

In Figs. 1, 2 and 3 the body of an ordinary cylindrical container or package is indicated at l and the cover or lid at'2. An outer decorative and advertising wrapper 3 is usually applied about the cylinder. In these views the top of the container is provided with a circular pouring opening 5 which is made by cutting a circular disk from the cover. This disk is cut out without waste of any of the stock and is preferably used to form a part of the closure. In the various views it is indicated by the numeral 6.

To complete the enclosure, 2. second or larger disk, indicated by the numeral 8, is cut from a stock of the same or substantially the same thickness as the stock from which the main container is made. This second disk is then formed by a die into the shape shown in full lines in Fig. 3 to form a depressed cup 9 and an outwardly extending flange H). The operation of forming the disk 8 into the cup shapeof Fig. 3 causes the edges of the stock which constitute the flange H] to fold or crinkle in the manner shown in Fig. 1, the dieing operation flattening out the flange so that it lies at right angles to the wall of the cup 9.

This element of the closure which may be designated as the skirt is now placed in the opening 5 in the position shown in dotted lines in Fig. 3 with the flange resting on the top of the container and with the base of the cup somewhat below the underside of the cover. The disk 5 is ,then pressed into the cup-shaped portion of the skirt and through the hole .5. This operation causes the disk to snap into place and expands the lower portion of the wall of the cup 9 which now assumes a bead-like form which interlocks the closure with the top of the carton. The projecting bead is indicated by the numeral I2.

Certain of the relative dimensional features of the device should be noted. The stock for the cover 2 should be relatively rigid so that it is not easily bent and will spring back into place when the closure is engaged. In actual embodiments of the invention, a fiberboard stock of a thickness of from .022" to .025" has been used, but any stock of the requisite stillness may be employed in lieu thereof. The stock for the skirt 8 may be of a like thickness and character, although a stock lighter than that used for the main body or top of the carton may be employed. The disk 6 has an outer diameter equal to the inner diameter of the opening and, as indicated above, it is desirable to use the material which has been removed to form the opening, although that is not essential. The disk should have the requisite rigidity so that it can be removed from and replaced in the opening repeatedly without losing its flat form. As the outer edge of the disk 6 and the inner edge of the opening 5 are of the same diameter, the bead 12 will have an outer diameter equal to the diameter of the opening 5 plus twice the thickness ofthe stock of the skirt and this is sufiicient to provide a secure interlock between the top of the container and the removable cap or closure, and yet the difference is not so great as to prevent the entrance of the cap with a distinct snapping action.

It is not necessary to assemble the elements in the order specified, as the disk 6 may be inserted in the skirt before the skirt is located in the opening -5, but the order stated previously is preferred as the edge of the container about the opening 5 assists in the correct formation of the bead l2 when that order of steps is followed.

When the elements of the closure have been once assembled, the disk 6 is securely interlocked in the skirt and will not separate therefrom so that the closure can be removed and replaced frequently.

In order to insure against tampering with the contents of the container before it reaches the consumer, the manufacturer of the commodity should provide some frangible retaining means to seal the closure in place. This may take any form, that shown in Figs. 1 and 2 being a seal or label I5 adhesively applied over the closure.

An adaptation of the invention to a square carton I8 is shown in Figs. 4 to 7 incl. The pouring opening may be located at any point on the six walls of the carton, but in the preferred form the opening 5 is located on one side near the top of the carton and close to one vertical edge thereof as shown in Fig. 4 so that the flange Ill projects slightly over the front wall of the carton. This location is preferred because the projecting portion of the flange provides a convenient means of removing the closure. A carton of this type is usually covered with a decorative and advertising wrapper indicated in dotted lines at 20 in Fig. 5. The wrapper 2ft is adhered to the carton and, therefore, serves the function of a seal, and when a wrapper is applied it is desirable to apply an arrow at to the wrapper for the purpose of indicating the point at which the projecting portion of the flange is located. A fingernail inserted at the point indicated will break the wrapper and the closure may be removed. In Fig. 6 the commencement of the operation is shown and in Fig. '7 the torn fragment of the wrapper is shown adhering to the closure.

In Fig. 8 the pouring opening is located in the top and near the rim of the circular container 2 so that the flange Ill projects over the outer periphery of the container where it is easily accessible. This form of the invention may be desirable where the entire container is enclosed by an outer wrapper.

It will be noted that in all forms of the invention a skirt 8 is made of a material which is relatively stifi, preferably of the same stock as the body of the container itself so that when the closure is once completed by forcing the disk 8 through the opening and into the cup-shaped portion of the skirt. the skirt forms about the edge of the disk and the bead l2 retains the disk in position without any adhesive connection between the disk and the skirt. The complete closure will snap into and out of place repeatedly without any deformation of the main body of the carton or of the bead I2. In the forms shown in Figs. 4 to 8 incl., the overhanging portion of the flange [0 gives an easy purchase by which the closure may be removed.

While it is preferred to make the disk in all of the forms from the stock removed to form the opening, this is not essential. Where the word wall is used in the claim, it is intended to refer to either the top or bottom of a container or any of the side walls thereof. While the opening in the container is preferably circular, it may be oval or of any desired configuration.

The fact that the label or seal IS in the form of the invention shown in Figs. 1 and 2 is adhesively applied to the top of the container and to the closure makes an easy method of retaining the closure in position to be reinserted in the opening after use, because it is necessary to tear only a portion of the seal to remove the closure from the opening. The untorn portion of the seal makes a convenient hinge about which the closure may pivot to open and close the pouring opening. In the same manner, the wrapper 20 in the form of the invention shown in Figs. 6 and 7 may likewise be employed as a hinge for the closure, it not being'necessary to tear out the wrapper all around the pouring opening 5 in order to remove the closure. The partially torn wrapper adhering to the closure is shown in Fig. 6. In the form of the invention shown in Figs, 6 and '7, the arrangement of the closure in position so that the flange projects outwardly beyond the adjacent side wall of the carton makes a bulge in the wrapper which indicates the point at which the user takes hold of the closure to open the package for the first time and thereafter to swing the closure back in position in the opening after removing a portion of the contents of the carton.

Since the retaining of the closure cap on the wrapper which covers it is an important feature of the invention, the word adhesively as used in the specification and in the claims is intended to mean that the wrapper and closure are bonded in substantially permanent fashion, as by glue or the like, so that the attaching bond is stronger than the tear resistance of the materials secured.

What is claimed is:

A container having an outer wall with a dispensing opening located adjacent a boundary of the wall, a closure for the opening having a depressed, cup-shaped portion insertable in the opening and having a beaded margin of greater diameter than the diameter of the opening, said closure also having an outer flange resting against the outer surface of the wall with a portion of the flange projecting outwardly beyond the boundary thereof, providing a tab for ready lifting of said closure, and with a diametrically opposite portion of the flange located within the said wall and spaced from the opposite boundary of the wall, and a frangible wrapper about the container, and adhesively attached to the outer surface of the said closure, in permanent fashion,

whereby when said tab is first lifted, the wrapper tears along a pair of parallel lines generally tangent to said closure providing a strip of the Wrapper to which the closure remains attached, and the end of which strip provides a hinge for repeated opening and closing of the opening by swinging of the closure.

DOUGLAS KIRK.

REFERENCES CITEFD The following references are of record in the file at this patent:

UNITED STATES PATENTS Number Name Date 786,957 Crane Apr. 11, 1905 868,721 Summers Oct. 22, 1907 891,878 Thatcher June 30, 1908 Number Number 10 8,867 of 1932 527,002 

